Light emitting devices are used in many different applications, including projection display systems, backlights for liquid crystal displays and the like. Projection systems often use one or more white light sources, such as high pressure mercury lamps. The white light beam is usually split into three primary colors, red, green and blue, and is directed to respective image forming spatial light modulators to produce an image for each primary color. The resulting primary-color image beams are combined and projected onto a projection screen for viewing.
More recently, light emitting diodes (LEDs) have been considered as an increasingly popular alternative to white light sources. LEDs have the potential to provide the brightness and operational lifetime that would compete with conventional light sources. A promising approach to LEDs for such applications is color converted LED technology, in which semiconductor color converting layers are used to efficiently convert short wavelength light into light of longer wavelengths. However, certain defects associated with color converting layers may result in both a reduction of performance and of lifetime. The present application seeks to address these defects.